Ontogenia da casta de soldados no cupim praga Heterotermoes tenuis (Isoptera, Rhinotermitidae)
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Data
2011-06-03
Autores
Laranjo, Lara Teixeira [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
Heterotermes tenuis é uma espécie de cupim nativa da região Neotropical, conhecida como praga agrícola e urbana. Essa espécie causa sérios danos econômicos em culturas de cana-de-açúcar e ataca madeiras e derivados celulósicos em cidades. H. tenuis apresenta hábitos subterrâneos e indivíduos de pequeno porte, com soldados dimórficos. A diferenciação de castas nos cupins é um processo complexo ainda não totalmente esclarecido. Em vista disso, o objetivo do presente estudo foi entender a diferenciação de soldados no cupim H. tenuis a partir de agrupamentos de operários. Para isso, no Capítulo I, foram apresentados os resultados dos bioensaios desenvolvidos para observar a influência de fatores extrínsecos e intrínsecos, entre eles, número de operários agrupados, temperatura, fontes alimentares e ingestão de diferentes concentrações de piriproxifen, um análogo de hormônio juvenil. Agrupamentos com 50, 100, 200 e 300 operários formaram uma baixa proporção de soldados. O uso de piriproxifen originou pré-soldados e também intercastas, sendo que a formação de pré-soldados foi maior na concentração de 10 ppm. Já no Capítulo II, o foco do estudo foram as mudanças morfológicas externas e internas ocorridas durante o processo de diferenciação de soldados. Para isso, operários, pré-soldados, soldados e intercastas foram submetidos à análise biométrica e histológica. Além disso, foi realizada a identificação do sexo dos soldados e a determinação da duração do ínstar de pré-soldado. Este ínstar durou cerca de 15 dias em temperatura ambiente e os pré-soldados diferiram biometricamente dos soldados, principalmente, pelo comprimento da cápsula cefálica e do tórax. As intercastas obtidas foram do tipo operário-soldado. Soldados menores de H. tenuis foram todos machos enquanto os soldados maiores apresentaram uma proporção de aproximadamente...
Heterotermes tenuis is a native species of termite, known as an agricultural and urban pest. This species causes serious economic damages on crops of sugar cane and attacks wood and cellulosic derivatives in cities. H. tenuis has subterranean habits and small individuals, with dimorphic soldiers. Differentiation of castes in termites is a complex process not yet fully understood. In this study we aimed to understand the differentiation of H. tenuis soldiers, originated from groups of workers. In Chapter I, we presented the results of bioassays developed to observe the influence of extrinsic and intrinsic factors, including, number of grouped workers, temperature, food sources and ingestion by the workers of different concentrations of pyriproxyfen, a juvenile hormone analog. Groups of 50, 100, 200 and 300 workers originated a low proportion of soldiers. The use of pyriproxyfen induced presoldiers and also intercastes. Presoldiers were produced in a large number in a concentration of 10 ppm. In Chapter II, the focus of the study was the external and internal morphological changes occurred during the process of differentiation of soldiers. For that, workers, presoldiers, soldiers and intercastas were histologically and morphometrically analyzed. In addition, we performed the sex identification of the soldiers and determined the duration of the presoldier instar. This instar lasted about 15 days at a variable temperature and the presoldiers biometrically differed from soldiers mainly by the length of head capsule and thorax. The intercastes obtained were from the worker-soldier type. Minor soldiers of H. tenuis were all males while the major soldiers had a ratio of approximately 1:1 between males and females. The exocrine glands of the individuals studied were compared and the histology showed that workers had greater development of the salivary, mandibular and sternal glands... (Complete abstract click electronic access below)
Heterotermes tenuis is a native species of termite, known as an agricultural and urban pest. This species causes serious economic damages on crops of sugar cane and attacks wood and cellulosic derivatives in cities. H. tenuis has subterranean habits and small individuals, with dimorphic soldiers. Differentiation of castes in termites is a complex process not yet fully understood. In this study we aimed to understand the differentiation of H. tenuis soldiers, originated from groups of workers. In Chapter I, we presented the results of bioassays developed to observe the influence of extrinsic and intrinsic factors, including, number of grouped workers, temperature, food sources and ingestion by the workers of different concentrations of pyriproxyfen, a juvenile hormone analog. Groups of 50, 100, 200 and 300 workers originated a low proportion of soldiers. The use of pyriproxyfen induced presoldiers and also intercastes. Presoldiers were produced in a large number in a concentration of 10 ppm. In Chapter II, the focus of the study was the external and internal morphological changes occurred during the process of differentiation of soldiers. For that, workers, presoldiers, soldiers and intercastas were histologically and morphometrically analyzed. In addition, we performed the sex identification of the soldiers and determined the duration of the presoldier instar. This instar lasted about 15 days at a variable temperature and the presoldiers biometrically differed from soldiers mainly by the length of head capsule and thorax. The intercastes obtained were from the worker-soldier type. Minor soldiers of H. tenuis were all males while the major soldiers had a ratio of approximately 1:1 between males and females. The exocrine glands of the individuals studied were compared and the histology showed that workers had greater development of the salivary, mandibular and sternal glands... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Térmita, Casta, Isoptera, Soldados (Cupim), Intercastas, Pré-soldados (Cupim), Caste differentiation, Presoldiers, Soldiers, Intercastes
Como citar
LARANJO, Lara Teixeira. Ontogenia da casta de soldados no cupim praga Heterotermoes tenuis (Isoptera, Rhinotermitidae). 2011. 177 f. Dissertação (mestrado) - Universidade Estadual Paulista, Instituto de Biociências de Rio Claro, 2011.